When a pregnant woman has cramps while sleeping, if we exclude the reasons caused by cold or fatigue, it is common to see a calcium deficiency in the body. Because the calcium consumption of pregnant women’s body is relatively large, the weight gain is relatively rapid, causing the legs to bear a heavy burden, resulting in the leg muscles in a state of overload fatigue. If the calcium supplementation is not timely, it can easily cause leg cramps during sleep, often occurring at night after sleeping. If leg cramps occur, you should immediately straighten your leg to the heel position and then slowly hook your toes up and back to shorten the cramp time. If there is no relief within a short period of time after calcium supplementation or if the symptoms are progressively aggravated, you must go to a regular hospital for further standardized treatment under the guidance of a doctor.